1. Field of the Invention
The present invention relates to a small-sized three-axis antenna which is used in a receiving system of a keyless entry system or a security system, etc.
2. Description of the Related Art
In recent years, a three-axis antenna, which is omni-directional and can be installed in a miniaturized receiving system, has been used widely as an antenna for LF band which is used in the receiving set, called as a fob, of a keyless entry system or of a security system for vehicles.
FIG. 4 is a perspective view of a conventional three-axis antenna 1. The three-axis antenna 1 includes an X axis coil 4x, a Y axis coil 4y and a Z axis coil 4z, the coils being orthogonally wound around a ferrite core 2 which is configured as a flat octangular body having fan-shaped auricles.
The core 2 is set on a resin base 3 to which a plurality of metal terminals are implanted, and the terminals of the X axis coil 4x, the Y axis coil 4y and the Z axis coil 4z are wound around winding portions 5a of metal terminals 5 and soldered to be electrically connected.